高强混凝土T形截面双向压弯构件承载力的研究

对9根T形截面高强混凝土双向压弯构件进行试验研究,揭示了这类构件的破坏形态,并进一步分析T形截面正截面承载力的变化规律.     

葫芦岛蒙脱土的特征与催化活性

研究了葫芦岛蒙脱土的某些特征与催化活性。该蒙脱石的离子交换能力与层间距分别是７５ｍｅｑ／１００ｇ和１．５２９ｎｍ，对偏三甲苯的歧化、异构化以及偏四甲苯的脱甲基、异构化都具有催化活性。这些数据表明葫芦岛蒙脱土是一种有用的催化材料。     

活性炭共吸附现象对有机蒸气穿透容量的影响

在空气避有机蒸气的气相色谱分析方法研究中，为获得可靠的采样效果，探讨了活性炭对共存有机蒸气的共吸附与穿透容量的关系，试验了四种有机蒸气共存时和组分的有采样效率。结果表明，共吸附使所有共存有机蒸气的穿透容量下降，共吸附物质愈多，穿透窝量下降愈严重。对二种和四种有机蒸气的共吸附，使丙酮的穿透容量下降２１．９％和４１．７％，四组分共存时，丙酮，丁酮，环已酮、甲苯的穿透窝量分别为５．６、５．０、９．７、１     

嵌岩灌注桩的竖向承载力研究

结合实测和试验资料，从理论上分析嵌岩灌注桩竖向承载力问题，及其各种影响因素。归纳总结了确定嵌岩灌注桩的承载力方法。     

镁合金及镁基复合材料阻尼性能研究进展

简要介绍了纯镁、镁合金及镁基复合材料的位错型阻尼机理,叙述了温度、合金成分、组织结构和微观缺陷(包括晶界相界)以及热处理等因素对镁合金阻尼性能的影响.镁基复合材料较镁合金有较高的阻尼性能,是由于增加了多种阻尼机制的结果,其中最重要的是塑性区阻尼、位错密度的增大、界面滑移阻尼等.     

High-Temperature Strength of Niobium Alloy 5VMTs with a Silicide-Ceramic Coating. Part 1. Short-Term Strength Characteristics

Experimental data on the short-term strength and plasticity of niobium alloy 5VMTs of the system Nb–W–Mo–Zr in its initial state, after annealing, and with a silicide-ceramic protective coating obtained by testing in vacuum, an inert atmosphere, and in air in the temperature range from 290 to 2270 K are analyzed. The process of microcrack initiation and propagation in the protective coating and matrix is investigated in high-temperature static tension. The limiting plastic strain values have been established at which the composite retains its load-carrying capacity in high- temperature aggressive and oxidizing gas atmospheres.     

Physical and Electrochemical Properties of Doped LiFePO4 as Cathode Material for Lithium-Ion Batteries

LiFePO4 cathode material was synthesized by a solid-state reaction using doping several elements (Nb5 ,Zr4 ). The starting materials were mixed with a high-efficient sander and treated thermally under flowing N2. The samples were characterized by X-ray diffraction (XRD), field-emission gun electron microscopy (FEG), and their electrochemical performance was investigated in the term of cycling behavior. Room temperature discharge capacity about 140.6 mA·h·g-1 was obtained at C/5 rate.     

Consideration on Effective Diffusivity of Strontium in Granite

Abstract

Diffusive behavior of strontium and certain kinds of divalent cations in Inada granite were studied by a through-diffusion method. In order to examine the effect of sorption onto overall diffusive behavior, two kinds of solutions were used: 0.1M KCl solution and deionized water. The effective diffusion coefficient (D_e ) and rock capacity factor (a) were (2.0–3.6) xl0–¹³ m²/s and less than 0.022 in 0.1M KCl solution and (0.32–1.7) x 10 ^?13m²/s and 1.5–2.4 in deionized water respectively. The D_e , and α in deionized water were much larger than those in 0.1M KCl solution. These results are well explained by taking into account the diffusion of sorbed ion or the surface diffusion. In support of this mechanism, most D_e , values of Sr reported for various rocks are found proportional to the sorptivity ( _ρR_d )-In the case that the sorptivity is low, D_e of Sr depends on porosity like that of nonsorbed iodide. The effective diffusion coefficient of Sr in rocks was well explained by taking into account pore and surface diffusion and was expressed as D_e=2.1 xl0^?10 _? ^1.3+3.5xl0″^?12 _ρR_d . The effective diffusion coefficient of divalent cations in the granite was found proportional to their diffusion coefficients in bulk solution.     

DHDECMP-TBP/煤油萃取 HNO_3-稀土过程中防止形成第二有机相的研究

研究了ＤＨＤＥＣＭＰ－ＴＢＰ／煤油萃取ＨＮＯ３后形成和防止形成第二有机相的各影响因素。以Ｇｄ代表稀土，探讨了ＤＨＤＥＣＭＰ－ＴＢＰ／煤油萃取稀土时ＤＨＤＥＣＭＰ浓度、ＴＢＰ浓度、水相ＨＮＯ３浓度和温度对有机相萃取负载量的影响。结果表明：０．６０ｍｏｌ／ＬＤＨＤＥＣＭＰ－１．４０ｍｏｌ／ＬＴＢＰ／煤油能有效避免第二有机相的形成，又能满足工艺负载量的要求。     

受水流冲刷影响后的吸力桶基础水平极限承载力

以某海域海上风机吸力桶基础为研究对象,采用Abaqus有限元数值模拟软件,考虑基础在不同土层中由水流冲刷导致其周围土体缺失时吸力桶基础的水平承载力。结果表明,桶内土体的缺失对吸力桶水平承载力的影响不大,随着吸力桶基础外周围土体缺失的扩大,其水平承载力逐渐降低,并影响海上风机的正常使用。